(1) Field of the Invention
The present invention relates to a shielded connector having a structure for carrying out the electromagnetic shielding and grounding to be used for connecting shielded wires to an equipment and the like.
(2) Description of the Related Art
FIG. 6 illustrates an example of a conventional shielded connector to be mounted on a motor vehicle or an electric vehicle. A part of the shielded connector 75 (a female connector 77) is similar to one disclosed in Japanese Patent Application Laid-Open No. H11-126657.
The shielded connector 75 consists of a male connector 76 and the female connector 77. In the present specification, a connector having a connector receiving chamber 78 is defined as the female connector 77 (the left side connector in FIG. 6) while a connector having a part to be received into the connector receiving chamber 78 is defined as the male connector 76 (the right side connector in FIG. 6). FIG. 6 shows a state in which the male and female connectors, 76 and 77, respectively, are fit with each other. The female connector 77 is directly mounted on a connector-mounting wall 79 made of electrically conductive metal of an equipment.
The male connector 76 has a female terminal 81 inside its inner housing 80 made of synthetic resin, then the terminal 81 is connected to a core 83 of a shielded wire 82. The shielded wire 82 consists of the core 83, an inner coat 84 made of electrically insulating resin coating the core 83, a woven metal shield 85 made of electrically conductive metal surrounding the outside of the inner coat 84, and an outer coat 86 made of electrically insulating resin coating the woven metal shield 85.
The woven metal shield 85 is connected to an end of cylindrical shielding shell 87 made of electrically conductive metal at the male connector side and the shielding shell 87 is disposed outside the inner housing 80. The inner housing 80 integrally continues to an outer housing 88 which has a locking arm 89 engaging with the mating female connector 77.
The female connector 77 has a male terminal 91 inside its connector housing 90 made of synthetic resin, an electric contact part of which protrudes in the connector receiving chamber 78. The male terminal 91 is connected to a wire 92 of the equipment side. A cylindrical shielding shell 93 made of electrically conductive metal at the female connector side is disposed along an inner wall surface of the connector receiving chamber 78.
The shielding shell 93 at the female connector side has one resilient contact part 94 coming in contact with the shielding shell 87 at the male connector side at one end of the shielding shell 93 and another resilient contact part 95 coming in contact with the connector-mounting wall 79 of the equipment at another end of the shielding shell 93. The another resilient contact part 95 has a plurality of spring pieces, wherein each spring piece resiliently comes in contact with an inner circumferential surface of a hole in the wall 79 so as to ground both shielding shells 87 and 93. Thereby, noises of electromagnetic waves from the outside of the shielded connector 75, those generated inside the shielded connector 75 and those transmitted through the shielded wire 82 are eliminated to the outside of the shielded connector 75, thereby bad effects of the noises against the equipment are removed. A rear holder 96, which is attached to the rear end of the connector housing 90, prevents the shielding shell 93 from coming off.
However, in the conventional structure of the shielded connector described above, there is a possibility that the permanent strain against the connector-mounting wall 79 and the wear caused by hitting of the resilient contact part 95 of the shielding shell 93 arises being influenced by the strong vibrations during the traveling of the vehicle and the temperature change in the temperature cycle, thereby the shielding performance (i.e., performance of electromagnetic shielding) for the shielded connector deteriorates. In addition, since the contact with the connector-mounting wall 79 is carried out by the resilient contact part 95, therefore the resilient contact part 95 or the inner circumferential surface of the hole in the connector-mounting wall 79 needs surface treatment for wear-resistance or electric conduction with the object of securing the durability, thereby a great deal of time are required and the shielded connector costs high. Furthermore, since the shape of the resilient contact part 95 is complicated, therefore the cost of the shielding shell 93 becomes high.
It is therefore an objective of the present invention to solve the above problem and to provide a shielded connector, by which the grounding with respect to the connector-mounting wall of the equipment can be always stably carried out without the permanent strain and the wear of the resilient contact part in a severe environment such as the mounting on the vehicle, the electromagnetic shielding performance can be maintained stable, a high electromagnetic shielding performance can be attained, and the cost of the surface treatment of the connector-mounting wall and that of the resilient contact part having a complicated shape can be reduced.
In order to attain the above objective, the present invention is to provide a shielded connector comprising:
a first connector having a first inner housing for receiving a first terminal connected to a shielded wire and an electrically conductive shielding shell, which is coated on the outer circumference of the first inner housing and connected to a shielded part of the shielded wire; and
a second connector having an electrically conductive shielded terminal resiliently coming in contact with the outer circumference of the shielding shell, an electrically conductive outer housing coming in contact with the shielded terminal for receiving the shielded terminal, a second inner housing inserted in the outer housing, a second terminal inserted in the second inner housing, and an electrically conductive connecting member, which is integrally formed with the outer housing and fixed on a connector-mounting wall of ground side with fixing means.
With the constitution described above, by an engagement between the first and second connectors, the shielded part of the shielded wire, the shielding shell, the shielded terminal, the electrically conductive outer housing and the connecting member are electrically connected with each other, and in addition, the connecting member is firmly fixed on the connector-mounting wall of the ground side with the fixing means. Therefore, noises from the shielded wire are stably grounded and noises from an equipment are stably grounded to the woven metal shield, thereby the electromagnetic shielding performance can be improved. Especially, instead of the ground connection with the connector-mounting wall by the conventional resilient contact part, a direct grounding is carried out from the connecting member of the electrically conductive outer housing. Therefore, even in a severe environment of the mounting on a vehicle such as vibration and temperature change, the ground connection to the connector-mounting wall of an equipment and the like can be always stably carried out, thereby the electromagnetic shielding performance can be stably maintained high.
Moreover, since the connecting member integrally formed with the electrically conductive outer housing is firmly bonded to the connector-mounting wall by face contact, therefore the shielding shell employing the conventional resilient contact part and the surface treatment of the connector-mounting wall for the purpose of improving the durability are not needed any more, thereby the structure of the shielded connector can be simplified and the cost thereof can be reduced.
Preferably, the shielding shell, the shielded terminal, the outer housing and the connecting member are made of non-magnetic material.
With the constitution described above, no magnetism is generated, for example, due to the external magnetic field, and no new noise is arisen, thereby the electromagnetic shielding performance improves.
Preferably, the shielded terminal has a plurality of resilient contact pieces, which come in contact with the shielding shell, inside the shielded terminal.
With the constitution described above, the electric resistance between the shielding shell and the shielded terminal reduces, thereby the shielding and grounding performance can be excellently maintained.
Preferably, the outer circumference of the shielded terminal comes in contact with the inner circumference of the outer housing.
With the constitution described above, since the shielding shell presses the resilient contact piece inside the shielded terminal toward the outside and the outer circumference of the shielded terminal strongly comes in contact with the inner circumference of the outer housing, therefore the electric connection between the shielding shell and the outer housing is securely carried out, thereby the electromagnetic shielding performance improves.
Preferably, the connecting member is a flange, which is fixed on the connector-mounting wall with a bolt as the fixing means.
With the constitution described above, since the flange of the outer housing strongly comes in contact with the connector-mounting wall of the grounding side by the bolting, therefore the electric connection between the outer housing and the connector-mounting wall improves, thereby the shielding and grounding performance improves.
Preferably, the second inner housing is locked into the outer housing with locking means.
With the constitution described above, since the inner housing can be easily fixed to the outer housing by the locking means, therefore the workability of the mounting and the desorption upon the maintenance improves. In addition, by means of the electrically insulating inner housing, the insulating performance of the second terminal with respect to the electrically conductive outer housing can be excellently secured.